Prince William and his wife, Kate, have released three new photographs of Princess Charlotte ahead of her fourth birthday Thursday.

Kensington Palace said the photos were taken by Kate, the Duchess of Cambridge, in April at Kensington Palace in London and at the family's country home in Norfolk.

Charlotte is the royal couple's middle child, between 5-year-old Prince George and 1-year-old Prince Louis.

She is fourth in the line of succession for the British throne, after her grandfather, Prince Charles; her father, William; and her brother George.